The Future of our Race. ALFRED R. WALLACE thus reviews a recent work by De Candolle on the Doctrine of Natural Selection: In the last section, on the probable future of the human race, we have the following remarkable speculations, very different from the Utopian views held by most evolutionists, but founded nevertheless on certain very practical considerations. In the next few hundred or a thousand years the chief alterations will be the extinction of all the less dominant races and the partition of the world among the three great persistent types, the whites, blacks, and Chinese, each of which will occupy those portions of the globe for which they are best adapted. But taking a more extended glance into the future of 50,000 or 100,000 years hence, and supposing that no cosmical changes occur to destroy the human race, there are certain well ascertained facts on which to found a notion of what must by that time have occurred. In the first place, all the coal and all metals available will then have been exhausted, and even if men succeed in finding other sources of heat and are able to extract the metals thinly diffused through the soil, yet these products must become far dearer and less available for general use than now. Railroads and steamships, and everything that depends upon the possession of large quantities of cheap metals, will then be impossible, and sedentary agricultural populations in warm and fertile regions will be best off. Population will have lingered longest around the greatest masses of coal and iron, but will finally become most densely aggregated within the tropics. But other and more serious changes will result in the gradual diminution and deterioration of the terrestrial surface.

Assuming the undoubted fact that all our existing land is wearing away and being carried into the sea, but, by a strange oversight, leaving out altogether the counteracting internal forces which for countless ages past seem always to have raised ample tracts above the sea as fast as sub-aërial denudation has lowered them, it is argued that even if all the land does not disappear and man so finally become extinct, the land will at least become less varied and will consist chiefly of a few flat and parched-up plains and volcanic or coralline islands. Population will by this time have greatly diminished, but it is thought that an intelligent and persevering race may even then prosper. They will enjoy the happiness which results from a peaceable existence, for without metals or combustibles it will be difficult to form fleets to rule the seas or great armies to ravage the land.

Volition and Reproduction.

IN continuation of the observations of Mr. Potts on the retention of eggs by birds, in our February number, we present the following very interesting account and deductions by the Rev. Dr. Wilson, of Easton, Maryland: The common house wren (T. Edon) lays from five to six eggs, and raises two

broods, depositing an egg every morning. Last summer I observed a pair in my garden anxiously seeking accommodations, but seemingly hard to satisfy, as the season was advanced, and others of the species were already sitting. I placed a box against an outbuilding, and within a half-hour they had commenced the nest. When three eggs had been laid a vagabond boy destroyed the nest. I saw him and gave chase, when he dropped the box and I replaced it. In two days the nest had been repaired; and when four eggs were laid the same irrepressible little barbarian carried off the box. Two days elapsed; the injured pair meanwhile flitting about and singing as if nothing had happened. I bored a hole in the building, and fitted another box inside: in twenty minutes the first stick was laid, and soon a nest had been formed with all the care of a first structure. Next morning an egg was laid, which I unfortunately broke. It made no difference-six more were deposited, the brood reared, the nest pulled to pieces, every stick and hair being carried to a distance, another nest constructed, and five eggs laid for a second brood, which was also reared successfully. Now here was the first laying delayed by the difficulty in selecting a place; the first clutch interrupted, the second also checked, and the first egg of the third broken, and yet in natural course there should have been an egg laid daily until six were deposited. Instead of eleven eggs for the two broods, nineteen were certainly laid by the same female that season; and if, as is probable, two eggs were matured which could not be retained, but had to be dropped anywhere, twenty-one, or nearly two seasons' layings, were extruded. Will that bird become sterile a year earlier than natural in consequence? But the chief point of interest lies in the fact that three several times the regular maturation of eggs was voluntarily checked under the influence of adverse circumstances, while an entire clutch and several additional ova were matured, which should not have been extruded until next summer! Now the question is, if the law of ovarian development is substantially the same in all vertebrata, may not some very important results be obtained from investigation based on these data in regard to the effect of mental emotion and volition upon the reproductive function? Facts of minor practical interest may be developed of great usefulness to all stock-breeders, and especially to those of domestic poultry.

Asphalt Pavements and Fire.

THE Journal of the Society of Arts states that during the reign of the Commune in Paris, in 1871, the fires made by incendiaries were never known to have been spread by means of the asphalt pavements. In London experiments were made on this point by heaping wood on the Val de Travers pavement and setting fire to it. When the fire was at its fiercest the burning embers were raked away, and only a few feeble flames were seen to issue from the pavement, and they went out directly of their own accord.

In the stables of the Paris Omnibus Company the grain loft is immediately over the stables, and to protect the oats from the effluvium from the stables the floor of the loft was covered with a thick layer of asphalt. In five different conflagrations this floor arrested the course of the flames until help could be procured.

A wooden floor covered with asphalt was also perfectly protected against a fire which was lighted on the asphalt; for though this substance gives off a volatile material which is inflammable and burns, the mass of lime and coke which remains is sufficient to protect the wood against the flames.

Intelligence in Young Creatures.

CONCERNING Herbert Spencer's ideas on this subject Mr. Spalding remarks: "Mr. Spencer has made the unqualified statement that a chick, immediately after it comes out of the egg, not only balances itself and runs about, but picks up fragments of food, thus showing us that it can adjust its muscular movements in a way appropriate for grasping an object in a position that is accurately perceived." The fact is, that on emerging

from the shell, the chick can no more do anything of all this than can the new-born child run about and gather blackberries. But between the two there is this great difference, that whereas the chick can pick about perfectly in less than twenty-four hours, the child is not similarly master of its movements in as many months. Our present point is, that it can be shown

by experiments that the performances of the chick a day old, which involve the perceptions of distance and direction by the eye and the ear, and of many other qualities of external things, are not in any degree the result of its individual experiences.

Mr. Spalding then passes to the discussion of Professor Bain's account of the growth of voluntary power, in which that gentleman says: "The infant is unable to masticate; a morsel put into its mouth at first usually tumbles out. But if there occur spontaneous movements of the tongue, mouth or jaw, giving birth to a strong relish, these movements are sustained and begin to be associated with the sensations, so that after a time there grows up a firm connection." But, says Mr. Spalding, we must remember that when the child is born it has no occasion for the power of masticating solid food; the ability to suck, which involves an equally complex series of muscular adjustments, is what it requires, and this it has by instinct ;— bearing all this in mind, the question is, why may not the innate ability to masticate be developed by the time it is required quite as spontaneously as the teeth required in the operation?"

Alcohol in the System.

DUPRE adds his testimony in support of the opinion that alcohol is consumed in the body. The results of two series of experiments showed, Ist, that the amount of alcohol eliminated per day does not increase with the

continuance of the alcohol diet, therefore all the alcohol consumed daily must of necessity be disposed of daily, and as it certainly is not eliminated within that time it must be destroyed in the system. 2d, the elimination of alcohol following the taking of a dose or doses thereof is completed 24 hours after the last dose is taken. 3d, the total amount of alcohol eliminated is only a minute fraction of that consumed.

Western Coal Measures.

As the result of an examination of the upper coal measures west of the Alleghanies, Prof. J. J. Stevenson deduces the following conclusions:

Ist. The Great Bituminous Trough west of the Alleghanies does not owe its basin-shape primarily to the Apalachian revolution.

2d. The coal measures of this basin were not united to those of Indiana and Illinois at any time posterior to the lower coal-measure epoch, and probably were always distinct.

3d. The upper coal-measures originally extended as far west as the Muskingum River in Ohio.

general condition was one of subsidence interrupted by longer or shorter intervals of repose. During subsidence the Pittsburgh marsh crept up the shore, and at each of the longer intervals of repose pushed out seaward upon the advancing land, thus giving rise to the successive coal-beds of the upper coal measures.

4th. Throughout the upper coal-measure epoch the

5th. The Pittsburgh marsh had its origin in the east.

Refining Sugar.

IN an article on the use of animal charcoal in sugar refining, Mr. Divis states that it is a mistake to suppose that the revivification of the charcoal is aided by the conversion into carbonate of lime of the lime that has been separated. On adding hydrochloric acid to the carbonate, the small masses of charcoal are quickly covered with a layer of carbonic acid derived from the carbonate of lime: whereas, if the lime is allowed to remain in the caustic state it dissolves in the acid without effervescence, and the removal of the impurity takes place more quickly and thoroughly. Having satisfied himself that the lime is in the caustic state, Mr. Divis goes on to propose the use of sal ammoniac as a means for the revivification of the charcoal.

Economy in Illumination.

MR. OFFERT states that in bats-wing burners, though the size of the flame diminishes with the amount of gas consumed, it is not in equal ratio. The light of a large flame, for example, may be equivalent to fifteen candles, while that of two small ones together will be only seven or eight candles, though they burn the same amount of gas as the large flame. This is caused by the complete combustion of the gas in the blue zone of the flame, which gives little or no light in either case and has more favorable circumstances for its occurrence relatively to the size of the flame in the small than in the large flame.

A singular fact in connection with gas flames is, that the power of the light is the same whether the flame is tested edgewise or flatwise. The conclusion arrived at is, that the use of cylindrical glass chimneys with round jets (Argand) is on the whole the most economical.

Preserving Iron Ships.

PROFESSOR CALVERT says:-I have made many experiments with the view of discovering the cause of the preservative action which alkaline solutions exert on iron, but have failed. Knowing the destructive influence which sea-water has on iron, and the serious injury resulting from the action of bilge-water in iron ships, a series of experiments was made with sea-water to which was added such a quantity of caustic soda or potash or their carbonates, that, after the salts of lime and magnesia were decomposed, there still remained in the solutions 1 to 5 per cent. of alkalies or the alkaline carbonates, and when iron blades were introduced into such liquids, they gave the same results as when iron had been dipped into an alkaline

solution of Manchester water. I would propose, in

conclusion, that a certain quantity of soda-ash should be introduced from time to time into the bilge-water of iron ships, as by so doing a great saving would be effected, since it would prevent the rapid destruction of such ships.

Memoranda.

M. CHANTRAN finds, that when the eyes of crayfish are exsected during the first year, they are completely restored after a few castings of the shell and perfect vision is regained. In old crayfish, on the contrary, the restoration is incomplete and imperfect.

An instance is given in The American Artisan in which typhoid fever attacked one-half the families in a village that used milk from a certain dairy. On making an investigation, it was found that the cows drank water from an old underground tank of wood which was decayed, and water from which doubtless found its way into the milk-cans in other ways than through the udders of the cows.

M. Gayon, as the results of experiments on the putrefaction of eggs, finds, 1st, that shaking the eggs has little or no appearance of effect on the act of putrefaction; 2d, that putrefaction is attended with the formation of vibrios; and, 3d, that the germs of these organisms are in all probability derived from the oviduct of the bird.

Experiments by MM. Estor and Saint-Pierre show that when glucose is injected into the blood-vessels it is consumed, its disappearance being attended by a consumption of oxygen and proportional production of carbonic acid.

THE world is wide awake to-day,
The laziest drones are bustling,
The brook slips by, the wind is gay,
And every leaf is rustling;

This shady bank, 'neath Beech and Oak,
With lance-like grasses bristles,
And you and I, two idle folk,

Sit making willow whistles.

Oh, heavenly sunshine of the May,

Succeeding winter hoary,
What shade can shut its light away,

What gloom resist its glory!
Down through our leafy canopy

Dart myriad golden missiles, And gild the brook, the bank, the tree,

And e'en the willow whistles.

Such wealth of leaf! such worlds of green!
Such balm, no words can utter !
And all the birds that e'er were seen,
Have gathered here to flutter:
They pertly perch, with heads awry

Upon the swaying thistles,

And evidently wonder why

We're making willow whistles.

How dare you, comrade, trifle so,
In these grand forest temples,
And laugh, and beat your sappy bough,
And set me bad examples !
Such songs of praises here arise,

As ne'er were found in Missals, ·
And we should hearken, were we wise,
Instead of making whistles.

They say the world's a vale of tears,
And man is born to trouble,-
The words sound idly in my ears

Beside the brooklet's bubble;
Friends change, I hear, and hopes grow pale,
The fairest project fizzles,—

I'm glad there's no such word as fail
In making willow whistles.

The brook shows back two heads of brown, Though one's a prettier color,

A Titian hue,-no need to frown,

I've said not which is duller; They'll be the same, both yours and mine, When time their brownness grizzles, And then, we'll laugh at 'Auld Lang Syne,' When we made willow whistles.

VOL. VI.

I WAS never fully satisfied with my explorations of the Upper Yellowstone region in 1870. What I then saw, and the discoveries made by Dr. Hayden's Geological Corps in 1871, begot in me the desire again to visit that Wonderland, with a view more fully to examine the surroundings of those particular localities which had so greatly excited the curiosity of the public. Our distress at the loss of a comrade,* and the little time we had for extended observation and careful description of what we saw, convinced me that the half had not been seen or told of the freaks of nature in this secluded wilderness. One of the most remarkable as well as valuable discoveries-the Mammoth Hot Springs at

See "Thirty-seven Days of Peril; " SCRIBNER'S for November, 1871. VOL. VI.-9

| Gardiner River-was reserved to be the grandest trophy of Dr. Hayden's Expedition. It was with the hope, therefore, that I might more fully comprehend what I had seen, and aid somewhat in the discovery of other wonders, that I concluded to avail myself of an invitation from Dr. Hayden to join his U. S. Geological Survey in July last, and accompany it in its visit to the National Park.

With a view to explore the country south of the Yellowstone, and especially in the immediate vicinity of Snake River, of which so many, almost fabulous, stories had been told,-Dr. Hayden placed his assistant, Captain James Stevenson, in charge of a part of his company, with instructions to approach the Park from that direction, while he, with the other members of the expedition, should proceed over the route of the previous year